Improvement in lifting-jacks for dumping-carts



u n. B.' LITTLE.,

l 'Impvrov'ement n Lifting .lackfof DumpingCarts.

YPatented Dec. '19, 18.71.

IlIFll I i i l l i i I I l i i I UNITED STATES PATENT OFFICE.

ROBERT B. LITTLE, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO HENRY BLUNDELL, AGENT, OF SAME PLACE.

IMPROVEMENT'IN LlFTlNG-JACKS FOR DUMPlNG-CARTS.

Specification forming' part of Letters Patent No. 122,036, dated December 19, 1871.

eculiar casino' a screw-s indle A)ivoted at ts` lower end to a suitable base-block, a gear-nut, and a bevel driving-gear mounted on a crankshaft; Iand I do hereby declare that the following` specification, taken in connection with the drawin g furnished and formingapart ofthe same, is a clear, true, and exact description thereof.

Referring to the drawing', Figure l represents one of my jacks applied to a dumping-cart. Fig. 2 represents the same in vertical section.

A represents the screw-spindle. Its lower end is pivoted to a base-block, B, provided with suitable bolt-holes, by which it is to be firmly fixed at or near the front axle of a cart, as shown in the drawing. (l represents a gear-nut fitted to the screw-spindle, and located within a casing, D, with bearings at top and bottom of the said casing, through which the bearings extend. E represents a bevel-gear mounted on the crankshaft, and iitted to engage with the gear-nut C, causing it to revolve in its bearings and longitudinally traverse the main spindle. F represents a spindle-casin g, which consists of a heavy tubular chamber of a length nearly equal to that of the scre\v-spindle, and somewhat longer than that portion ofthe spindle which projects above the casing D. G represents a head-block, in this instance pivoted to the spindle-casing F on one side at or near its top. This head-block is provided With bolt-holes by which it may be atcached to the front end of a dumping-cart body, as shown in the drawing. The form of the headblock can be varied, as good results will be at* tained if the upper end of the casing F be arranged to engage withthe under side of a strong sheltl projecting from the front ofthe cart, or the gear-Casin g D lnay be arranged to engage with the cart body.

The operation of my improved jack is obviously too well known to require explanation, as similar jacks have been long in use 5 but liever have they, to my k nowled ge, before my invention, been wholly protected from injury,` dirt, and dust, within a casing. lt will be readily seen that the screw-spindle will never be at all exposed to injury, eXcept during the brief operation of dumping, and that dirt cannot a'ect either the screw or the gearing, as such matter as may adhere to the screw when exposed will be cleared" as the nut proceeds. It is well known how important it is to protect a screw from injuries liable to be received from blows or knocks, which bruise or break the threads and render it impossible to operate it.

y Having thus described inyinvention, I claim as new and desire to secure by Letters Patenti The improved lifting-jack for dumping-carts herein described, consisting of the screw-spindle, gear-nut, and crankgear, combined and arranged Within the gear-casing D and spindle-casing F, substantially as described.

` ROBERT B. LITTLE.

Witnesses SAM. B. SWAN, 

